PPM pDS METERS
Operation Instructions
User Manual for Models T2/pH
T6/pH
2450 Impala Drive
Carlsbad, CA 92010-7226 USA
Tel 760-438-2021
Fax 800-869-7668 / 760-931-9189
www.myronl.com
pH/Conductivity Instrumentation
Accuracy • Reliability • Simplicity
DESCRIPTION
This manual describes your Myron L pDS meter , tells you how to
use it, and how to keep it working accurately for many years.
Myron L pDS Meters are compact, light-weight, self-contained
conductivity/pH meters. They contain a built-in sample cell with a
replaceable pH sensor. Models T2/pH and T6/pH convert conductivity
values directly to Total Dissolved Solids (TDS), and have dials
calibrated in parts per million and in pH units. They will quickly
determine the TDS and pH of almost any solution.
Both are 3.4" x 4.5" x 4.0" (85 x 129 x 126mm) and weigh less
than one pound (.45 kg). pDS Meters are completely self-contained.
The built-in cell is automatically temperature compensated from 50°
to 160°F (10° to 71°C). They are powered by a 9 volt transistor battery
good for at least 2000 tests, or one year shelf life.
MODEL PARTS PER MILLION (PPM) pH RANGE
RANGES
T2/pH 0-50, 0-500, 0-5000 ppm TDS 2-12 pH
T6/pH 0-5000 ppm TDS 2-12 pH
ACCURACY (Both Models)
TDS: ±2% of full scale (ppm NaCI standard only); Ground water
(442 standard) values are approximate because of varying
sample TDS compositions (see ACCESSORIES).
pH: ±0.2 pH units
REPEATABILITY: (Both Models) ±1%
By using an RE-10 Range Extender (see ACCESSORIES), the
maximum TDS range of each meter may be increased ten times.
The pictures in this manual show the major operating parts of
your Myron L pDS Meter . Handle your pDS Meter and identify these
parts to become familiar with it.
USING YOUR METER
TDS MEASUREMENT: Model T2/pH
1. Turn the Range Switch to the desired range. If you don't know
which range to use, set it to 1000.
2. Rinse the cell cup three times with the sample you want to test.
(For very hot or very cold samples see TEMPERATURE
COMPENSATION below.)
NEVER FILL CELL BY DIPPING METER INTO WATER!
3. Fill the cell with another sample to at least
upper electrode.
4. Press the black button.
5. Read the dial's black scale value indicated by the pointer. If the
pointer is very low on the left or goes off the scale to the right, try
the next lower or higher range.
6. MuItiply the dial's black scale value by the range setting to
determine TDS in parts per million.
7. If the pointer goes off the scale to the right on the x1000 range,
try RANGE DOUBLING (see FIELD CALIBRATION) or use an
RE-10 range extender (see ACCESSORIES).
TDS MEASUREMENT: Model T6/pH
1. Rinse and fill the cell cup as in steps 2 and 3 above.
2. Press the black button.
3. Read the TDS value in parts per million indicated by the pointer
on the dial's black scale.
4. If the pointer goes off the scale to the right, try RANGE DOUBLING
(see FIELD CALIBRATION) or use an RE10 range extender (see
ACCESSORIES).
NOTE: When finished, RINSE THE CELL CUP with clean water,
preferably distilled or deionized.
pH MEASUREMENT
1. Obtain sample to be tested, if necessary, heat or cool it to between
50° and 160°F (10°-71°C).
2. Remove the pH compartment cap and sharply shake out any
liquid.
3. Pour or squirt the sample into the built-in cell cup, especially the
small pH compartment. Shake out and repeat three times with
the sample to be tested. These may be the same rinsings used
to condition the cell for the TDS measurement.
4. Press the red button. The pointer immediately indicates the
pH of the sample on the red scale. If the pointer drifts, wait
approximately 30 seconds and press the button again to obtain
a stable reading of pH. If drifting continues, the electrode may be
coated with a film. Use a liquid cleaner such as Windex
Fantastic
™
clean the pH sensor bulb (see pH SENSOR).
5. Rinse both pH and conductivity parts of the cell with clean water.
LEAVE SOME LlOUID IN AND RECAP THE pH
COMPARTMENT.
TEMPERATURE COMPENSATION: For very hot or very cold
solutions let the three rinse samples each remain in the cell for several
seconds, then immediately fill the cell with the sample you want to
test (step 3 above). This allows the automatic temperature
compensation feature time to work properly.
CAUTION:
ALWAYS store your pH sensor wet and with the cap on.
ALWAYS rinse the cell cup with pure water immediately
after use or cleaning. This will prevent the build-up of deposits and
possible contamination of the sample.
DO NOT test solutions which could damage the pH sensor. See
MAINTENANCE.
DO NOT use with samples hotter than 160°F (71°C). The readings
WILL NOT be accurate.
DO NOT splash solvents such as lacquer thinner, acetone, benzene
or chlorinated solvents on the plastic case.
DO NOT fix or modify the meter. That will void your warranty. See
SERVICE for details or consult Myron L
DO NOT DIP THE INSTRUMENT INTO W ATER. If water does get
inside the instrument, see MAINTENANCE for instructions on drying
it.
1
/4" (6mm) above the
™
or
TDS CALIBRA TION
TDS ST ANDARD SOLUTIONS: A Standard Solution has a known
conductivity and ppm/TDS. Y our meter was calibrated at the factory
using Standard Solutions. You can keep your meter accurate by
using these same Standard Solutions. 442 Standard Solutions
approximate the conductivity characteristics of most natural waters.
To pick the right Standard Solution for your meter see
ACCESSORIES.
How often you calibrate your meter depends on how much you
use it. For once a day use, recalibrate it every three months.
CHECKING TDS CALIBRATION
1. Turn Range Switch to the x1000 range (T2/pH only).
2. Test a sample of appropriate Standard Solution.
CAUTION: Throw away the Standard Solution as you use it. Don't
put the used samples back in the bottle.
3. If the pDS Meter does not indicate the same value as is on the
Standard Solution bottle's label, first clean the cell. For directions
on how to do this see CELL CUP inside. Rinse the cell thoroughly
and test the Standard Solution again. If the pDS Meter still does
not indicate the correct value, recalibrate it as described below.
TO RECALIBRATE TDS
1. Remove the bottom cover using fingernails or a small screwdriver
to loosen the front or rear edge. Identify the TDS Calibration
Control(s) so you can find them by touch while calibrating (Model
T2/pH has three; see photo below).
2. Test another sample of the Standard Solution (be careful to not
splash solution inside the meter).
3. Adjust the Master Calibration Control until the meter indicates
the value on the Standard Solution label.
NOTE: T2/pH and T6/pH Meters may be calibrated to read either
442 or NaCI parts per million, but not micromhos.
4. The Master Calibration Control on model T2/pH adjusts ail ranges.
For best accuracy in the lower ranges, get the recommended
Standard Solutions for the x100 and x10 ranges. Use the x100
and x10 trimmers to recalibrate those ranges as in steps 2 and 3
above.
5. Turn the Range Switch to "S" and press the black button (T2/
pH); or press the green button (T6/pH).
6. Compare the meter reading to the INTERNAL ST ANDARD value
on the meter's bottom label. If they are noticeably different, mark
the new value in place of the old one.
NOTE: The feature described below is intended as a quick field
calibration check, or for using the range doubling technique. It is not
a replacement for calibration with Standard Solution.
INTERNAL ST ANDARD: An INTERNAL STANDARD value for each
meter is on the label on the bottom cover of each meter. Use it
between normal calibrations as a field check of your meter's accuracy.
To verify your meter's calibration:
1. Turn the Range Switch to "S" and press the black button (T2/
pH); or press the green button (T6/pH).
2. If the reading matches the INTERNAL ST ANDARD value on the
bottom label, your meter is in calibration. If not, see TDS
CALIBRATION above.
FIELD CALIBRA TION/MAINTENANCE
1. Turn the range switch to "S" (T2/pH only).
2. Remove the bottom cover using fingernails or a small screwdriver
to loosen the front or rear edge.
3. Press the black button (T2/pH) or green button (T6/pH) and adjust
the Master Calibration Control until the meter reading is the same
as the INTERNAL STANDARD value.
NOTE: If the meter will not adjust to the INTERNAL STANDARD
value the battery should be replaced. See MAINTENANCE below.
4. Replace the bottom cover.
RANGE DOUBLING
1. Using procedures described above, adjust the INTERNAL
STANDARD to
2. Test sample. Multiply reading by two. For example: Indicated
value of 3200 ppm would actually be 6400 ppm (3200 x 2).
NOTE: After completing tests requiring range doubling, reset the
Master Calibration Control to its INTERNAL ST ANDARD value and
replace bottom cover.
pH STANDARD BUFFER SOLUTIONS
All pH sensors "drift" and decrease in strength as they age. pH
meters have two Calibration Controls to compensate for those effects.
ZERO adjust corrects for "drift" of the pH sensor's response to neutral
pH solutlons. GAIN adjust amplifies the signal from the pH sensor
for accurate readings of other pH values.
Use pH standard buffer solutions to calibrate all pDS meters. The
recommended values are 4, 7, and 10. For greatest accuracy, adjust
with the buffer closest in pH to the samples to be tested.
pH ZERO ADJUST (Frequency: weekly)
Test by rinsing and refilling the cell with 7 buffer and pressing the
red button. The meter should indicate 7 on the red scale. If it is
necessary to calibrate Zero, perform the following steps:
1. Remove the bottom cover using fingernails or a small screwdriver
to loosen the front or rear edge.
2. Refill cell with 7 buffer (see pH MEASUREMENT for proper
procedure).
3. Press the red button and turn the pH Zero control until the needle
indicates 7.
4. Recap the pH compartment and replace the bottom cover.
pH GAIN (SLOPE) ADJUST (Frequency: bi-monthly)
The Gain should be calibrated approximately once every eight
weeks. The Gain control is used with 4 and 10 buffers.
NOTE: Never adjust the Gain control without first adjusting Zero.
T est by rinsing and refilling the cell with 4 or 10 buffer and pressing
the red button. The meter should indicate the buffer value on the red
scale. If it is necessary to calibrate the Gain, perform the following
steps:
1. Remove the bottom cover.
2. Rinse and fill the pH compartment with 4 buffer and press the
red button. Adjust the Gain control until the needle indicates 4.
3. Rinse three times and test with 10 buffer. If adjustment is
necessary, adjust to only half way between the initial reading
and 10. If, after this, the 4 and 10 buffer readings are not less
than one division from 4 and 10, the sensor is deteriorating and
should be replaced. The sensor should also be replaced if the
Gain control cannot make the pointer reach either 4 or 10.
1
/2 the value shown on the bottom label.
MAINTENANCE
BATTERYCHECK Turn the Range Switch to "S" and press the black
button (T2/pH); or press the green button (T6/pH). If the pointer does
not reach the INTERNAL STANDARD value, readjust the "S" (see
TDS CALIBRATION). If the pointer will not reach the INTERNAL
STANDARD value, the battery should be replaced.
BATTERY REPLACEMENT To replace the battery, detach the
battery connector. Pull on the vinyl strap to remove the battery.
Replace with fresh zinc carbon or alkaline 9 volt battery. Reinsert
the vinyl strap to secure battery.
CELL CUP: Self-conditioning of the built-in electrodes occurs each
time the button is pressed with a sample in the cell cup. This ensures
consistent results each time. With some samples a small downward
swing of the pointer is a result of this conditioning action. This action
is powerful and removes normal films of oil and dirt. However, if very
dirty samples—particularly scaling types—are allowed to dry in the
cell cup, a film will build up. This film reduces accuracy . When there
are visible films of oil, dirt, or scale in the cell cup or on the electrodes,
scrub them lightly with a small brush and household cleanser. Rinse
out the cleanser and the meter is ready for accurate measurements.
pH SENSOR: The unique pH electrode in your pDS meter is a nonrefillable combination type which features a porous Teflon* liquid
junction (covered by U.S. Patent No. 4128468). It should not be
allowed to dry out (see pH MEASUREMENT). If it does, the sensor
can sometimes be renewed by soaking in a saturated potassium
chloride (KCI) solution for several days.
"Drifting" can be caused by a film on the sensor bulb. Use a liquid
cleaner such as Windex
™
or Fantastic™ to clean it. The sensor bulb
is very thin and delicate. Excessive pressure during cleaning may
break it.
Leaving high pH (alkaline) solutions in contact with the pH sensor
for long periods of time can damage it. Rinsing such liquids from the
pH compartment and moistening it with 4 buffer or tap water will
extend its useful life.
Samples containing chlorine, sulphur, or ammonia can "poison"
any pH electrode. If it is necessary to measure the pH of any such
sample, thoroughly rinse the pH sensor with clean water immediately
after taking the measurement. Any sample element which will reduce
(add an electron to) silver, such as cyanide, will attack the reference
electrode.
Replacement sensors are available onIy from the Myron L
Company or our authorized distributors (see ACCESSORIES).
™
DuPont Company
*
WATER INSIDE THE METER
Y our Myron L meter is a rugged instrument and will withstand water
exposure around its cell, meter movement and switches. However,
care should be taken to keep water from leaking in around the bottom
cover. It is not sealed (to prevent condensation from forming).
If the water is relatively clean (i.e., tap water or better), and there
are only a few drops inside the meter, dry it as described below.
Large amounts of water, or corrosive or very dirty solutions will almost
certainly damage the meter movement or electronics. Such meters
should be returned to the Myron L Company for repair.
To dry your meter:
1. Shake excess water out of the inside of the meter.
2. Dab the exposed surfaces dry with an absorbent cloth or tissue.
Avoid pushing any water into the Calibration Controls or the
switches.
3. Air dry the meter in a warm area with the bottom cover off. Allow
several hours for thorough drying.
If the water entered through a leak in the case or cell, or if the
instrument shows erratic readings or other unusual behavior, return
it to the Myron L Company for servicing.
ACCESSORIES
STANDARD SOLUTIONS
TDS STANDARD SOLUTIONS
Y our pDS Meter has been factory calibrated with the appropriate
Standard Solution. All Myron L conductivity Standard Solution bottle
labels show three values: ppm 442, ppm sodium chloride, and
conductivity in micromhos.
442: Unless otherwise specified, the calibration used for all DS Meters
is the "442" standard. The 442 Standard Solutions consist of the
following salt ratios: 40% sodium sulfate,40% sodium bicarbonate,
and 20% sodium chloride. This salt ratio has conductivity
characteristics approximating natural waters and was developed by
the Myron L Company over two decades ago.
Sodium Chloride: For every ppm 442 Standard Solution there is a
ppm sodium chloride (NaCI) solution which wili have the same
conductivity. The parts per million of the equivalent NaCI solution is
on each Standard Solution label. Instruments calibrated to NaCI
standards are set using equivalent NaCI values.
Conductivity: All Myron L Company Conductivity Standard Solutions
are within 1.0% of Potassium Chloride reference solutions. The
concentrations of the reference solutions are calculated from data in
the International Critical Tables, Vol. 6.
pH STANDARD BUFFER SOLUTIONS: Ready to use, Myron L
Company pH buffer solutions are mold inhibited and accurate to
within +0.06 pH units @ 25°C. They are traceable to National Bureau
of Standards certified pH references and are color-coded for instant
identification.
RECOMMENDED STANDARD SOLUTIONS
MODEL/RANGE SOLUTION NUMBER
T2/pH
TOT AL DISSOLVED SOLIDS:
X 10 442-30
X 100 442-300
X 1000 442-3000
with Re-10 442-30,000
pH ZERO 7 buffer
pH GAI N 4 buffer
10 buffer
T6/pH
TOT AL DISSOLVED SOLIDS: 442-3000
with RE-10 442-30,000
pH ZERO 7 buffer
pH GAIN 4 buffer
10 buffer
RANGE EXTENDER
The RE-10 Range Extender is a useful accessory for testing high
conductivity solutions beyond the normal range of your pDS meter.
Inserting the RE-10 into a sample-filled cell cup increases the
maximum range ten times. Use the Range Extender whenever the
reading is off the scale.
USING THE RE-10
1. Fill the cell cup three times to rinse it, but each time insert the
Range Extender to rinse it also.
2. Fill the cell cup with your sample. Push the Range Extender into
the cell cup, seating the O-ring seal.
3. Use and read the pDS Meter in the normal manner. Multiply the
reading by 10.
4. For best accuracy, repeat the complete test with a fresh sample.
5. When finished, remove the Range Extender. Thoroughly rinse
the cell cup and Extender with clean water (preferably distilled or
deionized) to eliminate dried salts build-up. This is extremely
important when the instrument will be used to test high purity
water.
pH Conductivity Instrumentation
Accuracy • Reliability • Simplicity
CALIBRATING THE RE-10
1. Calibrate your meter (without RE-10) using Standard Solution
number 442-3000.
2. Fill cell cup with 442-30,000 Standard Solution.
3. Insert RE-10and pressthe button. Multiply the reading by 10 and
compare it with the value on the Standard Solution label. If they
are not the same, the RE-10 must be recalibrated.
NOTE: DO NOT adjust the Conductivity Calibration Control.
4. Adjust the white insert of the Extender as follows: If the reading
is too high—push or tap inward.
If the reading is too low—twist or pull outward with pliers.
NOTE: The Range Extender is factory calibrated to a particular meter.
It should be recalibrated if it is to be used
with another meter.
PORT A PAK
Carrying Case for use with all
Myron L DS and pDS meters, is
foam-lined and molded of sturdy
ABS plastic.
REPLACEMENT pH SENSORS
Order Model RPY for either T2/pH or T6/pH meters. When ordering,
be sure to include the model and serial number of your meter to
ensure receiving the proper type. Complete installation instructions
are provided with each replacement sensor.
ORDERING
T o order accessories contact your nearest stocking distributor, or
the Myron L Company.
WARRANTY & SER VICE
Myron L pDS meters, excluding the pH sensor, have a two-
year warranty. The pH sensor has a 6 month limited warranty.
If an instrument fails to operate properly, check the batteries,
calibrations, and cleanliness of the pH sensor bulb. If it still fails
to properly function, return it prepaid to the Myron L Company.
If, in the opinion of the factory, failure was due to materials or
workmanship, repair or replacement will be made without charge.
A reasonable service charge will be made for diagnosis or repairs
due to normal wear, abuse or tampering. This warranty is limited
to the repair or replacement of the Myron L pDS meter only. The
Myron L Company assumes no other responsibility or liability.
2450 Impala Drive
Carlsbad, CA 92010-7226 USA
el 760-438-2021
T
Fax 800-869-7668 / 760-931-9189
www.myronl.com
© Myron L Company 2001 (W)Printed in U.S.A. Specifications subject to change without notice
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